1 files changed, 145 insertions, 0 deletions
diff --git a/mobile/android/services/src/main/java/org/mozilla/gecko/sync/JSONRecordFetcher.java b/mobile/android/services/src/main/java/org/mozilla/gecko/sync/JSONRecordFetcher.java
new file mode 100644
index 000000000..982b5b026
--- /dev/null
+++ b/mobile/android/services/src/main/java/org/mozilla/gecko/sync/JSONRecordFetcher.java
@@ -0,0 +1,145 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.sync;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import org.mozilla.gecko.background.common.log.Logger;
+import org.mozilla.gecko.sync.delegates.JSONRecordFetchDelegate;
+import org.mozilla.gecko.sync.net.AuthHeaderProvider;
+import org.mozilla.gecko.sync.net.SyncStorageRecordRequest;
+import org.mozilla.gecko.sync.net.SyncStorageRequestDelegate;
+import org.mozilla.gecko.sync.net.SyncStorageResponse;
+
+/**
+ * An object which fetches a chunk of JSON from a URI, using certain credentials,
+ * and informs its delegate of the result.
+ */
+public class JSONRecordFetcher {
+  private static final long DEFAULT_AWAIT_TIMEOUT_MSEC = 2 * 60 * 1000;   // Two minutes.
+  private static final String LOG_TAG = "JSONRecordFetcher";
+
+  protected final AuthHeaderProvider authHeaderProvider;
+  protected final String uri;
+  protected JSONRecordFetchDelegate delegate;
+
+  public JSONRecordFetcher(final String uri, final AuthHeaderProvider authHeaderProvider) {
+    if (uri == null) {
+      throw new IllegalArgumentException("uri must not be null");
+    }
+    this.uri = uri;
+    this.authHeaderProvider = authHeaderProvider;
+  }
+
+  protected String getURI() {
+    return this.uri;
+  }
+
+  private class JSONFetchHandler implements SyncStorageRequestDelegate {
+
+    // SyncStorageRequestDelegate methods for fetching.
+    @Override
+    public AuthHeaderProvider getAuthHeaderProvider() {
+      return authHeaderProvider;
+    }
+
+    @Override
+    public String ifUnmodifiedSince() {
+      return null;
+    }
+
+    @Override
+    public void handleRequestSuccess(SyncStorageResponse response) {
+      if (response.wasSuccessful()) {
+        try {
+          delegate.handleSuccess(response.jsonObjectBody());
+        } catch (Exception e) {
+          handleRequestError(e);
+        }
+        return;
+      }
+      handleRequestFailure(response);
+    }
+
+    @Override
+    public void handleRequestFailure(SyncStorageResponse response) {
+      delegate.handleFailure(response);
+    }
+
+    @Override
+    public void handleRequestError(Exception ex) {
+      delegate.handleError(ex);
+    }
+  }
+
+  public void fetch(final JSONRecordFetchDelegate delegate) {
+    this.delegate = delegate;
+    try {
+      final SyncStorageRecordRequest r = new SyncStorageRecordRequest(this.getURI());
+      r.delegate = new JSONFetchHandler();
+      r.get();
+    } catch (Exception e) {
+      delegate.handleError(e);
+    }
+  }
+
+  private class LatchedJSONRecordFetchDelegate implements JSONRecordFetchDelegate {
+    public ExtendedJSONObject body = null;
+    public Exception exception = null;
+    private final CountDownLatch latch;
+
+    public LatchedJSONRecordFetchDelegate(CountDownLatch latch) {
+      this.latch = latch;
+    }
+
+    @Override
+    public void handleFailure(SyncStorageResponse response) {
+      this.exception = new HTTPFailureException(response);
+      latch.countDown();
+    }
+
+    @Override
+    public void handleError(Exception e) {
+      this.exception = e;
+      latch.countDown();
+    }
+
+    @Override
+    public void handleSuccess(ExtendedJSONObject body) {
+      this.body = body;
+      latch.countDown();
+    }
+  }
+
+  /**
+   * Fetch the info record, blocking until it returns.
+   * @return the info record.
+   */
+  public ExtendedJSONObject fetchBlocking() throws HTTPFailureException, Exception {
+    CountDownLatch latch = new CountDownLatch(1);
+    LatchedJSONRecordFetchDelegate delegate = new LatchedJSONRecordFetchDelegate(latch);
+    this.delegate = delegate;
+    this.fetch(delegate);
+
+    // Sanity wait: the resource itself will time out and throw after two
+    // minutes, so we just want to avoid coding errors causing us to block
+    // endlessly.
+    if (!latch.await(DEFAULT_AWAIT_TIMEOUT_MSEC, TimeUnit.MILLISECONDS)) {
+      Logger.warn(LOG_TAG, "Interrupted fetching info record.");
+      throw new InterruptedException("info fetch timed out.");
+    }
+
+    if (delegate.body != null) {
+      return delegate.body;
+    }
+
+    if (delegate.exception != null) {
+      throw delegate.exception;
+    }
+
+    throw new Exception("Unknown error.");
+  }
+}
+\ No newline at end of file